The Herb Gardener

by Jo Canning

In the world of gardening, herbs hold a unique place. It is the only group of plants who give us food, flavourings, ornamentals, perennials, medicines, aromas, and pest management all at the same time. This versatility makes herbs the perfect foundation perennials in any garden, whether you keep a large yard or have scaled down to a smaller urban footprint. Even minimalist apartment dwellers can have access to their favourite culinary herbs for these hardy perennials and annuals also grow well containers.

Herb or spice? These terms are used interchangeably, and often depend on how one cooks with the plant, rather than a strict definition. Most herbs are the aromatic leaves and stems of evergreen or herbaceous perennials used in cooking and medicine. A few, like the alliums and daikon, are bulbs or roots. Most are perennials, with a few important annuals, like basil, dill and coriander. Most plants we call herbs originated in temperate and Mediterranean climates. Most spices – the roots, seeds, bark, and fruits of perennials and trees — originated in warmer and tropical climates so are too tender for growing zones below Zone10. However, there are some spices– cumin, caraway, licorice and horseradish for example – which are half-hardy and grow well in a cool greenhouse or cold frame.

Garden Helpers

Herbs are the perfect plants to attract beneficial insects, those pest killers who ruin our flowers and vegetables. Some are mistaken for pests because gardeners see them at the sites of damage. The very ugly lady beetle larva is an example. It looks fearsome but is voracious predator of aphid. Others — like the miniature stingless wasp whose larvae kill pest caterpillars — are so small they look like the biting no-see-ums flies. Usually it is relatively easy to tell pest and “benny” apart. Pests are usually slow because they are busy munching and sucking on our precious plants. Beneficials move quickly: they hunt, scurry and buzz about, attacking the pests.

Over 80% of the insects you see in your garden are beneficial, so please, no pesticides – even “organic” ones — or you’ll also kill these valuable insects who help us at all stages of their variable lives. The flyers drink nectar and lay their eggs nearby. The larvae eat the pests. All you really need to keep your garden healthy is a combination of time-tested best gardening practices and beneficial insects, our important pest control partners.

Growers’ Notes

Roman chamomile (Anthemis nobilis, syn. Chamaemelum nobile) is a low mounding perennial. German chamomile (Matricaria recutita) is a self-seeding annual with lacy foliage. Although not invasive, you’ll be picking out young plants when you weed – unless, of course, you use the greenery, or want to wait until the plant flowers then harvest and dry the whole plant for tea.

Be very careful of mint (Mentha sp.) — the runner roots can quickly become invasive in milder climates. My favourite is chocolate mint which I keep under control in a large pot. I snip off the flowers and leaves and use both in salads, dessert garnishes and tea so the plant never goes to seed. Mint is a hardy evergreen so I use it fresh all year.

Another difficult herb is bronze fennel Foeniculum vulgare ‘purpureum‘ syn. rubrum). I love the stately look of it, and use the greenery in salads and seafood dishes – but I never let it go to seed in the open garden. I have grown a few plants for seed in a small patio green house, using most as a great breath freshener and stomachic, and saving some seed to grow out the next spring.

Lavender (Lavendula sp.) has, like sage and basil, many cultivars. If you use it for cooking, English lavender (Lavandula angustifolia) is your plant. I like the variety ‘Munstead.’ If you mix your own ‘Herbs de Provence’ use this variety, not the French variety (Lavandin) as it is too intense and very floral. Several other species are used for perfume and potpourri. Here is where the French lavender shines.

Scientific knowledge is all about carefully documented change, and rosemary is an example. Until recently, rosemary’s botanical name was Rosmarinus officinalis. Recent DNA research prompted botanists to shift it to the salvia genus (Salvia rosmarinus). You’ll find it under both labels. Garden centre employees are usually very knowledgeable so do not be afraid to ask.

Hardiness and Winter Storage

Many herbs are hardy to Zone 3 except in windy areas or in those mini-climates that get a winter freeze-and-thaw cycle so frost heaves expose roots. A couple of inches of mulch resolves this issue. Fallen leaves work well and provide both winter cover for native bees and other beneficials as well as spring food for the soil. Wait until the weather is close to freezing or just before the first snows arrive — this encourages hardiness — then mulch to the drip line, leaving a few inches of bare ground around the centre stems to keep them from rotting and give beneficial insects a place to over-winter in the dirt.

Rosemary (Salvia rosemarinus) looks like a hardy little conifer, but is actually one of the more tender herbs. The tall uptight cultivar is the most tender, so I learned to rely on the low-growing cultivars, the prostrata group. If your climate gets wet snow storms, tall rosemary can get crushed. Mine was in an exposed area so it got enough sun during the growing season but that made it vulnerable to winter’s mean times. After losing a couple of plants, I got smart. I protected it sudden freezes and wet snow with a tomato cage and a bit of row cover draped over the top. I pulled the snow away from the plant stem and piled it in a donut around the outside of the cage. The mini-berm stopped ground-level wind.

If you grow herbs in planters and bring them inside for winter, a basement, garage, or protected porch are good choices. They also keep more of their greenery so even the herbaceous types may offer a few leaves. A very light watering every other week will keep the soil damp and the root balls plump. A root cellar or cold greenhouse are also good choices; their natural humidity will keep the soil damp. Herbs grown in balcony planters are more vulnerable to winter damage but a small patio greenhouse or frost blanket will keep them healthy in the off season.

Herb Hardiness Zones:

Zone 3: caraway, chives, garlic, peppermint, parsley
Zone 4: garlic chives, lemon balm, lovage, sage, winter savory, tarragon, thyme
Zone 5: lavender, flavoured mint hybrids
Zone 6: Italian oregano (Zone 5 where protected)
Zone 7: Greek oregano, marjoram, rosemary
Zone 10: globe basil (Ocimum basilicum var. minimum)

During the winter months do not harvest more than 25% of evergreen herbs at a time or the plant will struggle next year, and may succumb to winter if in a marginal area. The solution — just grow more!

Success with Herbs for Culinary Use

Some of our culinary herbs are evergreen, and although some are herbaceous (dropping leaves and tender stems, or dying back to a crown at the end of the growing season), these often allow us to enjoy their flavours fresh all year in mild climates as they don’t go completely dormant and remain semi-evergreen.

As if to make up for their shorter life cycles, two culinary annuals are useful at several growth stages. Coriander (Coriandrum sativum) seed (spice) is used in soups, dals, and pickles. We also enjoy its leaves, called cilantro, as a signature flavour in Mexican and Spanish salsa. Dill (Anethum graveolens) greens give us the main flavour in dill pickles, salads, deviled eggs, poached fish, and vegetable dishes. The seed, technically a spice but known as a herb, is important in savoury breads, soups, and pickles.

Culinary savory has both an annual and perennial cultivar. Summer savory (Satureja hortensis) is the lanceolate-leaved annual whose flavour is often described as a cross between mint and thyme. Winter savory (Satureja montana) is the perennial. Its flavour is stronger than its annual cousin, and has a finishing hint of rosemary. I find the perennial suits me better because it is essential in my chicken recipes. It is also less work, and its late-blooming blossoms are tiny, cheerful white dots that attract late season beneficial insects.

Most cooks use at least eight herbs all the time, and another half dozen some of the time. Culinary manuals list 12 to 15 classic cooking herbs. Here are the most common perennial herbs:

chives (Allium schoenoprasum)
garlic (Allium sativum)
marjoram (Marjorana hortensis)
mint (mentha sps.)
oregano (Origanum vulgare)
parsley (Petroselinum sativum)
rosemary (Rosmarinus officinalis, syn. Salvia rosmarinus)
sage (Salvia officinalis)
winter savory (Satureja montana)
tarragon (Artemisia dracunculus)
thyme (Thymus vulgaris)

Here is the shorter annual plant list:

basil (Ocimum basilicum)
cilantro leaves (Coriandrum sativum)
dill (Anethum graveolens)
summer savory (Satureja hortensis)

Some herbs offer a dizzying array of cultivars that cater to different cuisines. I perused one seed catalogue which offered no less than ten basil cultivars boasting different scents, flavours and colours. I use two: the big leaf Genovese basil for fresh leaves and pesto, and the spicy globe basil for soups and Italian tomato dishes. If your recipes include Asian cuisines, some of the Thai cultivars may be better choices for you.

A note on globe basil: Ocimum basilicum var. minimum) is botanically a tender perennial, but only in Zone 9b-11. I’ve managed to overwinter it, but usually just grow it as an annual. It also needs – like the other annual herbs – a richer soil that perennial herbs. I also add a bit of worm castings and the occasional shot of liquid fish fertilizer to give a bountiful harvest. Pinching the top growth keeps it bushy and tender and helps delay flowering.

Know your botanical names when buying your culinary herbs. Different herbal genera and species are valued for different purposes and have different growing needs. Sage (Salvia sp.), used in food, medicine and cosmetics, has close to 1,000 named species yet only three are used in Western cooking: Salvia officinalis, with several cultivar s offering different colour (like purple) and flavours (like pineapple); Greek sage (S. fruticosa), and Salvia hispanica (the edible seed “chia”) which is high in fatty acids. Ornamental sages are labeled as “salvia.” Ask in the garden centres, and you’ll quickly learn the differences.

Preserving the Harvest

Drying herbs is easy. Herbs can survive happily with 40% of their growth removed if you need that much and it is still the growing season. Leave the primary stem structure intact and prune whole secondary branches with sharp pruners or scissors. (The strategy will also keep the shrub bushier when it breaks green in the spring.) Tie the bundle tightly, greens at the bottom, leaving enough string or wire to hook over a nail or hang on a cross-piece strung between two uprights. Hanging the plant upside down concentrates the natural oils in the leaves for more flavour. A brown paper bag secured loosely around each bundle will collect the leaves as they dry and fall off also keeping out dust and over-wintering insects. Hang in an airy, dry place out of direct sun. Basements, attics, cool greenhouses, front or back porch rafters work very well. A friend of mine used a clothes rack on her covered patio.

If your climate is humid, air drying is often a poor choice for some herbs like rosemary, sage and basil, as they can mould before they get dry. A small electric food dryer meant for home use is a good option. Mine ran happily for over 10 years, and what electricity I used was far less than what I would pay in the store for dried or fresh herbs. Although some people use their oven I do not like to heat up my kitchen in summer. And the oven environment makes an inferior product. Where the dryer can be set at exactly the correct temperature the oven can be difficult to keep an even temperature, and major flavour is lost if the temperature is too hot. A plant is ready to harvest when the leaves are crunchy, and come off the stems easily. Keep the bag around the bundle, open it up, reach inside and crush the plant. Compost bare stems and store the herbs in air tight containers.

An Enterprising End Note

In years past when I had a big harvest and too much for my own use or needed to prune back overgrown plants in mid-spring, I sold my extra dried and fresh product to local health food stores. Because the dryer allowed me to process larger quantities faster I could offer a safe, organic product for public consumption. It was a good way to trade with a store for produce. If you are motivated, the returns could also help pay for the modest investment of an electric dryer.